Needle bed for knitting machines



Feb. l5, 1938. R H. LAWSON ET AL i r NEEDLE BED FOR KNITTING MACHINES I I Filed' Feb. 20, 1935 I. mm

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Patented Feb. 15, 1938 UNITED STATES PATENT OFFICE NEEDLE BED FOR KNITTING MACHINES Robert H. Lawson and William L. Smith, .Jr.,

Pawtucket, R. 1., assignors to Hemphill Company, Central Falls, R. L, a corporation of Massachusetts 6 Claims.

This case is concerned with a needle bed for knitting machines, and more especially circular needle beds of the built-up type.

In the drawing:

Fig. 1 is a sectional view showing the needle walls and backing member secured to a cylinder;

Fig. 2 is a sectional view showing the soft metal cylinder in detail;

Fig. 3 is a view of one of the strips which forms the wall of a needle groove or trick;

Fig. 4 is a view showing one of the needle backing strips which is to be inserted between wall strips;

Fig. 5 is an end view of the strip shown in Fi 4;

Fig. 6 is a plan view showing a clamping segment;

Fig. is an elevation of the segment shown in Fig. 6. 20 The built-up cylinder of the type herein disclosed is especially adapted for use in machines having large cylinders such as knitting machines adapted to knit body fabric, which may be a rotating cylinder or a stationary cylinder depending upon the type of machine withwhich it is to be used. When forming large cylinders of this type the grooves or tricks'within which needles are to slide must be machined prior to hardening of the metal, but when hardened after such grooves have been cut a certain amount of warping takes place and the cylinder will not'run true. While we employ this built-up construction on a machine of the type herein described, the usefulness of the invention is not limited to machines of such size but is adapted to any knitting machine having independent needles.

Referring to Fig. 1, a cylinder l is shown attached at its lower end to a rotating ring gear 2 in'case of a rotating cylinder machine, or in the case of a stationary cylinder machine, said. cylinder would attach directly to a circular base or the like. A stitch ring 3 is attached by means of suitable screws to the top of cylinder I and forms a continuation thereof. This stitch ring has grooves or slots 4 cut thereinwithin which the inner ends of sinkers are guided. A ring 5 is inserted within a shouldered portion of stitch ring 3 and serves to support the fabric as it is cast on the needles and is pulled down within said cylinder by means of a conventional take-up mechanism. This ring has slots 6 cut therein at intervals so that lint which tends to gather in sinker grooves 4 may be pushed into these slots and thus discharge from the machine.

Cylinder I has a plurality of evenly spaced vertical grooves cut therein within which the wall strips 1, shown in detail in Fig. 3, are inserted. These strips are preferably of hardened, wear resistant material and are of a thickness sufficient to properly space needles which reciprocate vertically between them. In between each of these wall members I is inserted a needle backing strip 8, Fig. 4. These backing strips are preferably of the same hardened material as the wall strips and are of a thickness to fill the space between such strips. When the cylinder has been built-up in this manner it will be of substantially true cylindrical form, and to all intents and purposes, is a unitary structure. The needles will be guided within tricks formed of hard, long wearing material which may be replaced in case of damage or after a long period of use.

Referring to Fig. 2, it may be seen that cylinder i has been slotted for the reception of wall strips at its upper end at 9, and again at spaced intervals at Ill and H. The intervening space between slotted portions l0 and II is interrupted by an annular boss [2, the purpose of which will be described later. Adjacent the topmost portion the cylinder has been undercut at I3 to receive an interlocking portion of strips 1.

Stitch ring 3 has a projection M which is slotted in the spaces intervening above the slots which have been described as cut in cylinder I. These slots are for the purpose of guiding the upper ends of needle backing strips. Arecess I5 is also machined insaid stitchring for the purpose of engaging a corresponding projection on the backing strips by means of which the same maybe positioned axially of the cylinder.

In Fig. 3 one of the strips which is to be inserted in grooves 9, I0 and II of the cylinder has been shown in detail. This strip isof sufficient depth to properly seat within said cylinder and to project from the same a sufficient distance to properly guide needles, jacks or both as the case may be. At the upper end said strip is formed with an inwardly projecting portion l6 which engages within slot 9 in the cylinder; directly below this is a projection I! which is adapted to fit within undercut l3 and a recess l8 has been formed about midway of the strip to engage boss I2 of a similar shape on said cylinder. When assembled in said cylinder as shown in Fig. l, the upper end of one of these strips is first inserted so that projection l1 will engage in undercut l3, and then the strip is pushed into its slot and locked therein by means of a series of sectors one of which is indicated at l9. These sectors are inserted against a shoulder 20 cut in the i in a short time.

strips I.

lower end of one of said strips and are secured in place by suitable bolts or screws. Adjacent ends of sectors are oppositely beveled as illustrated at 2|. When said strips have been inserted in the cylinder and sectors is fixed in place, they present a substantially unitary structure, it being necessary to remove one of the sectors if any of the strips 7 are to be withdrawn. It is,'however, a simple matter to remove the sector corresponding to any strip or group of strips which it is desired to replace and other strips may be inserted Each strip has a rectangular projection 22 adjacent its upper end and these form a substantially continuous ring about the upper end of said built-up cylinderon which a sinker supporting bracket may be clamped. Projections 23 and 24 define a space within which a plurality of springs are retained for holding needles and/r jacks within said built-up needle tricks.

The backing strip shown in Figs. 4 and is substantially straight: along its front edge and presentsa hard, wear resistant surface which is of sufiicient width to practically fill the space between adjacent wall members. In previous structures considerable difficulty has been experienced in maintaining these backing strips which are necessarily long and springy within the space between wall strips since it is not practical to clamp them in place as is done with the heavier To avoid this diflficulty cylinders have frequently been built up having only the wall strips of hardened material, it thenbeing necessary to rely upon thesoft metal of the cylinder to support the back of the needle. A great deal of wear would necessarily occur-when using such a construction. These strips as shown in Fig. 5 have been purposely formed with corrugations or a .seriesot kinks laterally thereof, so that when inserted between adjacent wall strips, they will be maintained in position by-the friction contact exerted by said corrugations. Fair results may be obtained by kinking these stripsrwhen assembling as many kinks being placed in the strips as would appear necessary, but the best results are obtained by preforming said stripswhen they are manufactured.

Each of these backingstrips has a projection 25 at its upper end which engages recess IS in the stitch ring. Each strip is recessed at 26, 27

and 2.8 to avoid projections 9, ii! and ii on said cylinder, and further,.has a carefully spaced recess 29 which engages boss 62 on the cylinder. he lower endxof said strip ,is-of the same depth as the corresponding portion. of strip 1 which projects beyond shoulder 2i? and seats within the :annular space between segment 59 and the base .of the needle cylinder.

It is tobe noted that the top portion of these backing strips projects upwardly beyond the adjacent wall strips and thus serves to support the back of its needle up to the appended claims.

We claim:

1. A needle bed for knitting machines having slots within which needles are adapted to slide, said slots being formed of hardened strips removably clamped in said bed to serve as the Walls of said slot, and other hardened strips between said first mentioned strips projecting from the surface of said bed a distance suflicient to form a backing for needles and held in place by a positioning lug and frictional engagement with said first mentioned strips, the construction being such that said second mentioned strips may be inserted or removed Without disturbance of the first mentioned strips or their clamping means.

2. A'needle bed for knitting machines having built-up slots within which needles are adapted to slide, said slots being formed of spaced strips forming walls and interspaced strips forming .the needlebacking members, said wall strips being inserted within grooves cut in a cylinder and maintaining in said grooves by interengaging portions on both strips and cylinder at their upper endsand'a ring seated under a shoulder at the lower end and clamping the same in position, and said interspaced backing strips having at least one recess which will engage a complementary annular boss on said cylinder and further being bent laterally so that they will be held in place by frictional engagement with said wall strips.

3. A metallic strip'for insertion as a needle backing strip in a cylinder having built-up needle slots, said strip having a straight needle bearing face and at least one recess for engaging an annular boss on said cylinder to position itself axially relative to said cylinder, and also being.

bent laterally so that when. inserted between adjacent wall strips, it will be frictionally held in place. 1

4. A metallic strip for insertion as a needle backing strip in a cylinder having built-up needle slots, said strip having a substantially straight needle bearing face and at least one interengaging portion for engagement with a complementary portion on said cylinder, thereby to position itself axially of the cylinder, said strip further being preformed with a series of lateral kinks therein so'that it will be frictionally retained between adjacent portions of said built-up needle slots.

5. A needle bed having at the upper portion thereof a sinker ring and a fabric engaging mem her, said sinker ring having slots thereinfor guiding the inner. ends of sinkers, a series of openings in said member and inalignment with the backing strip in a cylinder having built-up needle slots, said strip having asubstantially straight needle bearing face and at least one interengaging portion for engagement witha complementary portion on said cylinder, thereby to position itseli axially, of the cylinder, said strip being bent -laterallyso that when inserted between adjacent wall strips it will be frictionally held in place.

ROBERT E. LAWSON. WILLIAM L, SMITH, JR. 

